New high-resolution analysis of the {ν1 + ν3} band of the 15N16O2 isotopomer of nitrogen dioxide: Line positions and intensities

The high-resolution Fourier transform absorption spectrum of an isotopic sample of nitrogen dioxide, 15N16O2, was recorded in the 3.4 μm region. Starting from the results of a previous study [Y. Hamada, J. Mol. Struct. 242 (1991) 367-377] a new analysis of the ν1 + ν3 band located at 2858.7077 cm−1 has been performed. This new assignment concerns (1 0 1) energy levels involving rotational quantum numbers up to Ka = 10 and N = 54. Using a theoretical model which accounts for both the electron spin-rotation resonances within each vibrational state and the Coriolis interactions between the (1 2 0) and (1 0 1) vibrational states, the spin-rotation energy levels of the (1 0 1) vibrational state could be reproduced within their experimental uncertainty. In this way, the precise vibrational energy, rotational, spin-rotation, and coupling constants were achieved for the {(1 2 0), (1 0 1)} interacting states of 15N16O2. Using these parameters and the transition moment operator which was obtained for the main isotopic species, 14N16O2, a comprehensive list of the line positions and intensities was generated for the ν1 + ν3 band of 15N16O2.